<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>hello webgl</title>
</head>

<body>
    <canvas id="gl" width="400" height="400"></canvas>
</body>
<script>
    const canvas = document.getElementById('gl')
    const gl = canvas.getContext('webgl')
    gl.clearColor(0.0,0.0,0.0,1.0)
    gl.clear(gl.COLOR_BUFFER_BIT)
</script>

</html>